With “detecting the intactness of bath ground electrodes” it is also meant the detection of the intactness of the electrically conductive connection between the bath ground electrodes and the bath of the induction furnace.
A typical induction furnace contains one or more electrodes in the lower refractory lining of the furnace in order to assure that the metal melt in the interior of the bath is grounded. The intactness of these electrodes is decisive for the safe operation of an induction furnace since they provide an electrical connection between the melt bath and ground. This is a necessary presupposition for the effective operation of the ground fault monitoring in an induction furnace. If the refractory lining of the induction furnace is penetrated by the metallic melt and if the metallic melt in the crucible gets in contact with the induction furnace coil the coil is connected to the melt bath and finally to the grounded frame of the furnace through the bath ground electrodes in the bottom of the bath. In this manner a ground fault can be detected and then the power supply is switched off and an alarm is signaled to the operator of the furnace.